Page:The Zoologist, 4th series, vol 3 (1899).djvu/560

530 instance of passive mimicry? A similar observation was communicated to Mr. Trimen by Mrs. Barber. She was impressed by the behaviour of a male of the conspicuous butterfly, Papilio cenea, which twice deliberately selected in her garden, as a resting place during a shower of rain, a shrub whose pale yellow and brown seeds and flowers entirely agreed with the colouring of the under side of its wings. Of butterflies belonging to the Tropical American genus Siderone, Mr. Dent states:—"They always rest with wings folded over their bodies on branchlets, the markings and colouring of the under side of the wings resembling exactly dry brown or yellow leaves." Mr. Cornish has written:—"Many of the small blue British butterflies have greyish spotted backs to their wings. At night they fly regularly to sheltered corners on the chalk downs where they live, alight head downwards on the tops of the grasses which there flourish, and, closing and lowering their wings as far as possible, look exactly like a seed-head on the grasses." Mr. Carrington noticed for several evenings that a large White Cabbage Butterfly (Pieris brassicæ) searched out a few "sportive" whitish or creamcoloured leaves of a variety of ivy, and roosted upon one for the night. Mr. Trimen has observed the Satyrid butterfly Melanitis leda, which "rests among dead leaves on the ground in shady places, and is then indistinguishable from them"; and a parallel case, and a similar effect, is produced by the female Eronia leda, which settles on the faded bright yellow leaves of the Erythrina tree." Our well-known Orange-tip Butterfly (Euchloë cardamines), as observed by Mr. T.W. Wood towards evening or in cloudy weather, may be found at rest on the tops of grass or flowers, but more particularly on Anthriscus sylvestris, and almost always near that plant; the chequered white and green alone visible when the insect is at rest assimilates with the white flowers of the Anthriscus as seen against the green background. Attention has recently been called to what appears to